[MODNOTE: This post was moved top this forum for reasons expressed in post #9 below.]Hi guys,

I'm planning to do my first AG and first BIAB brew at the weekend and am wondering whether I need to do any water additions (salt/acids etc.)? I brew with rainwater from our tank at home in Perth, WA and am planning on making a London style porter, so there is a bit of chocolate/crystal malt and roasted barley in the grain bill. I've read that rainwater is effectively a blank slate for mineral salts etc. and this affects the enzyme activity and taste to a certain extent, but given this is my first BIAB I'd like to keep it as simple as possible so if I am able to brew a reasonable beer without getting into the water chemistry stuff just yet then that would be ideal!

Another option would be to replace some/all of the rainwater with tap water, since this would at least have some salts in it, although I don't know what the Perth water profile is like?

Any help would be greatly appreciated!

Paul

Last edited by paul_ulyett on 16 Dec 2014, 21:16, edited 1 time in total.

Ok, I have been using the brewersfriend.com water calculator and I can get the ion profiles right, but when I put in the grain bill I end up ~pH 5.8-6.0 and when I add some lactic acid addition to bring the pH down to ~5.4, this kills the HCO numbers compared to the target water profile, which makes sense since the acid is reacting to reduce the alkali (HCO).

is the HCO number in the water profile pre-grain addition? In which case I should ignore how that number changes after adding the acidic grain??

Yes... the water profile is your starting water, before any additions or mashing. Are you adding acid malt? Do you have pH test strips?

At any rate, for your first AG brewday just make sure the water you use tastes good and is free of chlorine and other contaminates. I brewed a brown ale a couple months ago and the pH was 5.9 and it turned out well.

BTW, that is a great tool but it is only a tool. You'll only get a handle on water once you start measuring, adjusting and tasting the results.

Thanks safebrew - I have put the grain bill into the Bru'n' water spreadsheet tool and tried to calculate the required salt additions - I can get everything to match up pretty well, with the exception of the HCO content - I need to add acid malt and some lactic acid to get the mash pH down to 5.2-5.5 range, this reacts with the HCO and reduces its concentration, so the water profile comes out with less alkalinity than the desired profile.

Any ideas as to how I can keep the HCO high enough while having a low enough Mash pH??

Thanks!

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Bicarbonate/Alkalinity doesn't matter if you are hitting your mash pH. There are no recommended values for these fields otherwise.

I don't understand why you are using lactic acid, and acid malt. Acid malt is a base malt that is sprayed with lactic acid. Any reason why you are using both?

Also not sure why you are bothering with chalk, baking soda and epsom salt. You should be able to hit your profile numbers with just gypsum and calcium chloride. Magnesium and Sodium can stay at 0, you're starting with rain/distilled water. You can ask martin why he chose those values for the profile, he'll likely say it was arbitrary ... or an educated guess by averaging typical tap water information.

Thanks Rick, good to know I'm more worried about pH than the HCO3 content - the reason I had all those salts instead of just gypsum & chalk was to hit the profile numbers better, maybe I'll simplify (especially for the first brew) and not worry too much about Mg & Cl.

I hadn't realised acid malt is just base sprayed with acid, the reason I had both was that otherwise I needed >3% by weight of lactic acid to reduce the pH sufficiently and had read that you should keep acid content below 3%.

Firstly, rainwater in a city is not the same as rainwater in the desert - nothing like it. It can be as impure as anything - Google, 'acid rain'.

Secondly, Perth water comes from many different sources and these change daily. Have you noticed that sometimes your drinking water tastes like shellfish?

Thirdly, you cannot adjust water unless you know what your water profile is and in Perth (and probably most parts of the world) you will never know this on a day to day basis. You really need to RO your water in most situations...

But, you should not be worried about your water at this stage of your career if you live in Perth and especially if brewing a Porter. I'll get a mod to move this to an advanced forum because water, assuming yours is drinkable, is the last thing that any new brewer should contemplate.

Concentrate on your recipe instead Paul.
PP

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Thanks PP - I did try and adjust my water in the end, but evidently didn't get it quite right as mash pH was down around 4.7-4.9. That being said, seemed to get the right amount of sugars out of the grain and the wort tasted alright to me going into the fermenter so we'll see how it comes out.......Was bubbling away merrily on Xmas day (much like myself) - so signs are good!

For the next AG batch, I'll take your advice and stick to the tap water without worrying about any water mods. Do you leave it to stand overnight to let the chlorine gas off - our tap water always tastes pretty chlorinated?

To remove chlorine either run it through a activated carbon filter or boil it. I use sodium thiosulphate at work to neutralise chlorine in water supplies before discharging to the environment, however I'm not sure if this will adversely affect the liquor????

I haven't been able to find any evidence that states sodium metabisulfate removes chlorine, but it definitely removes chlorimine. I have sent an email to a friend of mine who is a chemical engineer at a water treatment plant in Adelaide who will be able to confirm for me.

Joshua, in the article you have hyper linked there is no mention that sodium metabisulfite or as the article states 'potassium metabisulfite' neutralises chlorine in water, only that it neutralises chloramine in water. As I have said I cannot find any robust evidence, other than opinions on forums, that proves campden tablets will neutralise chlorine. I'm not a chemist and I don't have any sort of background in chemicals but I do know that chloramine and chlorine are 2 very different chemicals so one cannot assume that they can be treated the same way.

My original post was to highlight that the article http://morebeer.com/articles/removing_c ... from_water talks about neutraising "chloramine" not chlorine, as does everything else I have read in any brewing books about the use of campden tablets in brewing, including my copy of John Palmers How To Brew.

As I've said, I've emailed a friend who is a chemical engineer and hopefully he is able to clear this up for me when he gets back to me I'll post his answer.

Palmer in How to Brew, Palmer and Kaminski in the Water book and almost all pro and homebrewers refer to AJ deLange when talking about BOTH chlorine and chloramine removal with sodium or potassium metabisulfite (Campden). AJ deLange is the one of the foremost authorities in brewing water chemistry.

I have attached an essay of his below. The info in 5.6.1 should put this topic to bed... it is basically the same info that Mally gave you about Campden tablets. BTW... that section also give alternative methods of chlorine and chloramine reduction.

Jeff

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